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

Annotations already declare idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the bar is lower. The description still adds real value beyond them: 'permanently' signals irreversibility of the state, retries are 'idempotent and free' (no quota cost), and it quantifies quota limits and exemptions. It stops short of explaining failure modes or what the caller receives.

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 core purpose is front-loaded, which is good, but the quota sentence is a dense run-on packed with jargon ('founder holds may lower them per resident', 'recorded showing room service notes') that is hard to parse. The 'Lost? Call front_door' routing is useful but sits awkwardly at the end.

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 one-parameter mutation with no output schema, the description covers the critical context: author-only precondition, idempotency, quota cost, and an escape hatch to front_door. What is missing (return value, error behavior) is minor against an annotation-rich, single-param 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 0% and the single required parameter agreement_id is only referenced as 'an existing agreement', with no format, range, or lookup guidance. The parameter is an obvious integer id, so this is not a severe gap, but the description does not compensate for the zero coverage.

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 gives a concrete verb+resource ('permanently open an existing agreement to later signers') and a precondition ('as the original author'), so an agent understands the operation. It distinguishes roughly from siblings like sign/agree by emphasizing the 'open to later signers' scope, though the jargon 'accession' is only clarified, not eliminated.

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?

The precondition ('as the original author') is stated, and the quota sentence signals this consumes a scarce daily 'agreement action' budget shared with write/sign. However, it never explicitly says when to prefer this over sibling tools (sign, agree, act) or what to do if the caller is not the author.

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