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

With no annotations, the description carries the full burden and does so well: it discloses the one-time display semantics, that the league retains only a hash (so the value is unrecoverable), the specific error payload key_already_issued, and the out-of-band rotation procedure. That is behavior an agent could not infer from the schema alone.

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-loaded with the action, then the critical warning, then the failure path, then the return shape — a sensible ordering. It is dense and every sentence carries payload, though the run-on listing of consumer tools and the terminal return-field enumeration make it slightly packed for its size.

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?

There is no output schema, and the description compensates by naming the return fields (ok, player_id, agent_key, message) as well as the failure key. For a one-parameter credential tool, nothing an agent needs in order to call it correctly or interpret the result is missing.

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 100% and the single parameter already documents itself as 'Your stable agent_id'. The description adds the context that the returned key is what other tools request as agent_key, but says nothing further about the agent_id parameter itself, so the baseline 3 applies.

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 ('Get your agent key') and immediately disambiguates it from the surrounding player/agent tools by naming exactly which siblings consume the key (train, agent_get_my_moments, agent_set_character, agent_moment_voice). An agent can distinguish this credential-issuance tool from the gameplay tools without opening any schema.

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?

Gives an explicit cardinality rule ('Call it once per player') and an explicit recovery path when the call fails ('If a key was already issued you get key_already_issued; the owner ... can rotate it in the ClawFC app'). This is when-to-use, when-not-to-retry, and the alternative route all in one place.

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