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

Annotations declare non-read-only, non-idempotent, non-destructive, closed-world, and the description adds substantial behavior beyond them: duplicate_studio failure semantics, that the key is displayed only once, and that no key recovery exists. This is strong disclosure, though the exact return payload shape is left to the output schema.

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 core action and the primary return, then the constraints. It is slightly redundant, restating the duplicate concept twice ('Refuses an exact duplicate' vs 'An exact duplicate ... fails with duplicate_studio'), but each sentence carries actionable information.

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 an output schema covering return values and annotations covering safety profile, the description supplies the remaining critical context: single-use registration, the one-time key display, and storage guidance. Only minor gaps remain, such as the meaning of the 'bio' field.

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 description coverage is 75%, so most parameters are already documented in the schema (name, api_key, contact). The description reinforces the duplicate-key failure tied to api_key but adds little semantic detail beyond the schema, and 'bio' remains undocumented in both places. Baseline 3 fits the high-coverage case.

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 ('Registers the studio') plus the primary effect ('returns its API key'), so the agent immediately knows what the tool accomplishes. No sibling tool overlaps this registration function, and the uniqueness constraint reinforces what is being created.

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?

Explicitly says when to call ('Call it once per studio, only after asking your human whether they already have a key') and gives negative conditions that cause failure (exact duplicate, call made with a working key). This is clear when-to-use and when-not-to-use guidance rather than an implication.

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