agent-passport-system-mcp

Build Authority Evaluation Request

aps_capability_evaluate_authority

Read-onlyIdempotent

Evaluates a signed capability-token authority request, checking the M1 challenge, delegation chain, and token preimage so gateways can decide permit or deny.

Instructions

v0.1 capability-token authority evaluation request (M2). Subject signs a request carrying the sink's M1, the delegation chain, and a revealed authority-token preimage. The gateway consumes this to decide permit/deny. Search keywords: capability token, authority evaluation, M2.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "challenge": "<challenge>",
      "delegation_chain": "<delegation_chain>",
      "authority_token": "<authority_token>",
      "freshness_beacon": "<freshness_beacon>",
      "subject_private_key": "<subject_private_key>",
      "subject_public_key": "<subject_public_key>"
    },
    "name": "aps_capability_evaluate_authority"
  }
}

Input Schema

Name	Required	Description
`challenge`	Yes	SinkChallenge object from M1
`authority_token`	Yes
`delegation_chain`	Yes	v2.x delegation envelopes
`freshness_beacon`	Yes
`subject_public_key`	Yes	Subject Ed25519 public key (hex)
`subject_private_key`	Yes	Subject Ed25519 private key (hex)
`delegation_chain_root`	No	Override; otherwise computed from chain

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedv4.0.0Aug 1, 2026

changedInput schema / $schema

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

removedInput schema / additionalProperties
```
Removed value: -false
```
removedInput schema / properties / authority_token / additionalProperties
```
Removed value: -false
```
addedInput schema / properties / delegation_chain / items
```
Added value: +{}
```
removedInput schema / properties / freshness_beacon / additionalProperties
```
Removed value: -false
```

changedInput schema / required

Previous value: -[
-  "delegation_chain",
-  "authority_token",
-  "freshness_beacon",
-  "subject_private_key",
-  "subject_public_key"
-]New value: +[
+  "challenge",
+  "delegation_chain",
+  "authority_token",
+  "freshness_beacon",
+  "subject_private_key",
+  "subject_public_key"
+]

Addedv2.8.0May 1, 2026

TDQS

C2.9/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuine workflow context — it is an M2-stage request consumed by the gateway — but discloses nothing about failure modes, key-material handling, or what the tool returns. With annotations doing the heavy lifting, a 3 is appropriate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three compact sentences, with the role of the artifact and its consumer front-loaded. The trailing 'Search keywords' line is filler but conventional and does not bloat the definition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 7-parameter tool with nested objects and no output schema, the description omits what is returned (a signed request object) and what prerequisites must exist first (an M1 challenge). It conveys the stage in the flow but not enough for an agent to call it correctly without inspecting the schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 71%, so the schema documents most fields. The description maps three conceptual elements onto parameters (sink's M1 = challenge, delegation chain, revealed preimage = authority_token.token_preimage), which adds modest value, but freshness_beacon, subject keys, and delegation_chain_root are left to the schema. Baseline 3 given moderate coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose3/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a fairly specific action — the subject signs a request carrying the sink's M1, the delegation chain, and a revealed token preimage — but the tool name ('evaluate_authority') conflicts with the title/description ('Build ... Request'), leaving the agent unsure whether this tool decides permit/deny or merely constructs the input. The M1/M2 jargon is unexplained, so the resource is only partly clear.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no explicit when-to-use guidance and no routing against the closely related siblings (aps_capability_issue_challenge, aps_capability_mint_receipt, aps_capability_sign_effect). 'The gateway consumes this to decide permit/deny' describes downstream flow, not the condition under which an agent should call this tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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