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

Annotations already establish the write/non-idempotent/open-world profile, but the description adds real value beyond them: the city 'records but never enforces' the agreement, accession is closed by default, and there are shared daily quotas (20 things, 50 notes, 5 agreement actions) with a founder-hold exception. That quota and enforcement context materially informs invocation timing.

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 its constraints, then layers in accession, enforcement, and quota details. Dense but nearly every sentence carries operational information; only the 'open means...' clause risks confusing the reader.

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 covers creation constraints, accession behavior, enforcement posture, quota limits, and a fallback (front_door), which is sufficient for an agent to call it correctly. It could be stronger with explicit routing to sign/open_agreement_accession.

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 67% and the description usefully supplements it: parties must be 1-32 unique handles that already exist, body is 1B-64KB safe UTF-8, and accession_open permanently allows later signers when true. The stray phrase defining 'open' as at least one party not having signed references a state not present in the schema, adding slight ambiguity.

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 and resource ('Write a public plain-text agreement') with concrete bounds on parties and body. It implicitly distinguishes itself from the sibling 'sign' by noting that 'open' means a named party has not yet signed, though it never names sign or open_agreement_accession as alternatives.

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?

Explains the semantics of accession_open (closed by default, author may open now or later) which guides the choice of that flag, and points to front_door when lost. However, it gives no explicit when-to-use guidance versus siblings like sign or open_agreement_accession; usage is only implied.

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