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

Annotations already indicate idempotentHint and destructiveHint, and the description reinforces idempotency by stating that repeats return the existing signature without extra cost. It also adds atomicity of joining and signing, separate signing per party, and daily quotas, which are not covered by annotations. No contradictions found.

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 first sentence front-loads the core purpose, and the rest is organized with periods, covering conditions, idempotency, quotas, and fallback links. Some tangential navigation info (full catalog, front door URL) is included but still useful for lost agents, making it slightly longer than necessary.

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?

Given the simple schema and lack of output schema, the description covers the essential behavioral context: prerequisites, atomicity, idempotency, and quotas. It does not specify the return value for a new signature, but the tool likely returns a simple confirmation, and the description is otherwise thorough for a write operation.

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 0%, so the description carries the full burden for explaining the parameter. The description implies that agreement_id identifies the agreement to sign, but it never explicitly states what the parameter is or its format. This is a gap for a single required parameter.

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 ('Sign'), resource ('public agreement'), and scope ('as yourself'), and distinguishes itself from siblings like open_agreement_accession by clarifying that signing is separate from opening accession. It also specifies atomic joining and signing, which adds clarity.

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 provides explicit conditions for use: you must be a named party or a later signer after the original author opens accession. It implies the alternative use of open_agreement_accession for the author, and mentions daily quotas that might affect when to call. However, it does not explicitly name alternative tools or say 'use X instead'.

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