Echo SDK Invoke

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

Annotations already declare this as non-read-only and destructive, but the description adds valuable behavioral context: risky invocations require an approval token or env override, and idempotency_key plus retry/backoff are supported. It still leaves undefined what risky means and what side effects occur.

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?

The description is three short, front-loaded sentences with no filler. Purpose, gating requirements, and retry support are each communicated efficiently.

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?

For a destructive six-parameter tool with nested objects, the description covers the key approval and retry mechanics, and an output schema exists. However, with very low schema description coverage, it should do more to explain reason, payload, and params semantics.

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 description coverage is only 17%, so the description must compensate. It gives some meaning for capability, confirm, and idempotency_key, but it does not explain reason, payload, or the shape and semantics of params, leaving most parameters without meaningful guidance.

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 states a specific verb and resource: invoking an Echo SDK capability by exact capability ID with params. It is clear what the tool does, but it does not explicitly differentiate itself from the sibling tools search, write, and read.

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?

It gives an important usage condition for risky capabilities: confirm='SDK_INVOKE_APPROVED' unless ECHO_MCP_ALLOW_RISKY_SDK=1. However, it does not say when to use this tool versus alternatives such as search, write, or read, nor does it define what counts as a risky capability.

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