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

Annotations declare readOnlyHint=false and destructiveHint=false, so the agent already knows this mutates state without destroying data. The description usefully confirms that effect is limited to new stakes and that the pool enters a 'sunset phase,' which resolves the ambiguity about whether existing stakes are wiped. It still omits reversibility, whether the operation can be undone, and any permission requirements, so it adds context but not rich behavioral detail.

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?

Two short sentences, zero filler, with the core action and its scope front-loaded before the state consequence. Nothing can be removed without losing meaning.

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 annotations present and no output schema, the description covers the essential effect and the resulting state. It is adequate but leaves open what happens to existing stakes and whether the close is reversible, which an agent invoking an irreversible-looking lifecycle change might reasonably need.

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?

There is a single parameter (poolId) with 100% schema description coverage, so the schema already carries the semantics. The description adds nothing about the parameter, which is the expected baseline when the schema does the work.

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 ('Close an investment pool') with a scope qualifier ('to new stakes'), which clearly distinguishes it from sibling mutations like stake_in_pool, claim_pool, and create_investment_pool. It does not name or contrast with any sibling explicitly, so it lands at 4 rather than 5.

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 phrase 'to new stakes' implies the situation in which this tool applies (stopping new participation), but there is no explicit when-to-use guidance, no prerequisites (e.g., pool owner authority), and no exclusion or alternative named. Usage is inferable but not stated.

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