Server-side ed25519 receipt verifier

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

Annotations declare readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds context: it never returns 4xx for structurally well-formed bad signatures, returns 200 with valid:false, and details preimage recomputation logic. Adds value beyond annotations.

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

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

Three paragraphs: first explains what it does, second when to use, third parameter options and response behavior. Front-loaded with key action. Not overly verbose, but could be slightly more concise by omitting 'Algebra: verify.'

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

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

No output schema, but description explains return format ({valid, reason, pubkey_b32}) and HTTP behavior (200 for bad signatures). Covers input tolerances and edge cases. Complete for a crypto verification tool.

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

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

Schema coverage is 100%, so baseline is 3. The description adds that receipt must carry certain fields, that signature/pubkey can be byte[] or b32, and that pubkey_b32 is an optional override. This adds meaning beyond the schema descriptions.

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

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

The description clearly states the tool verifies a signed receipt envelope server-side, recomputes the canonical preimage, runs ed25519, and returns {valid, reason, pubkey_b32}. It uses a specific verb ('Verify') and resource ('receipt envelope'), and distinguishes itself from sibling tools by focusing on receipt verification.

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

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

Explicitly says when to use: 'when the in-browser /verify path is blocked... or when you want a server-side audit'. Implicitly, when the browser path works, use that instead. Provides clear context and alternatives.

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