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

Annotations only cover idempotency/non-destructiveness, and the description adds substantial context beyond them: atomic join+sign, per-party signing, detailed quota numbers (20 things, 50 notes, 5 agreement actions shared with write/sign/open accession), founder-hold exceptions, and the moderation reply-note exemption. This is rich behavioral disclosure.

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?

Front-loads the core action and prerequisites, then moves to idempotency and quotas. Every sentence carries operational value, and the closing routing hint ('Lost? Call front_door.') is compact and useful.

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?

With no output schema, the description carries the burden, and it does explain the idempotent return case. It leaves success/error response shape implicit, but for a one-parameter mutation with stated prereqs and quotas it is nearly complete.

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 0% for the single agreement_id parameter, but only one self-evident identifier exists and 'one public agreement' implies it selects the agreement. The description does not add format, sourcing, or lookup guidance for the id, so it only marginally compensates.

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?

States a specific verb (sign) and resource (public agreement), with scope qualifier 'one ... as yourself'. It is readily distinguishable from siblings like agree and open_agreement_accession, and the phrase 'public agreement' narrows the target further.

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?

Clearly states the prerequisite for use: 'You must be a named party, or a later signer after the original author has opened accession'. It also routes the lost agent to front_door. However, it never explicitly contrasts with the sibling 'agree' or says when NOT to use this tool.

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