Update a persona

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

Beyond annotations, the description discloses important behavioral side effects: avatar format/size restrictions, the username rename moving the profile immediately, old URLs breaking with no redirect, and the released name becoming claimable. This is exactly the kind of non-obvious behavior an agent needs to know before invoking the tool.

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 description is compact and front-loaded: the core update semantics appear first, followed by the avatar constraint, then the riskiest behavior (username rename). Every sentence carries necessary information with no filler or repetition of the title.

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 an update tool with six parameters and no output schema, the description covers the crucial call-facing concerns: what partial update means, how to supply avatars, and the destructive implications of renaming. The only notable gap is the lack of any mention of return value or confirmation behavior, and no explicit routing against sibling tools.

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 100%, so the baseline is 3. The tool description adds meaningful cross-parameter semantics: partial-update behavior, accepted avatar encodings and format/size limits, and the move-not-alias consequence of changing username. These details go beyond the individual schema property descriptions.

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 clearly states a specific action — 'Partial update of one of your personas' — and immediately distinguishes it from create/delete/set operations by emphasizing the partial, patch-like nature. This also differentiates it from siblings like create_persona and set_default_persona without ambiguity.

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 description gives clear context: it is for updating an already-existing persona, and 'omitted fields are left alone' tells the agent how to express partial updates. It does not explicitly list excluded sibling tools or when-not-to-use conditions, but the usage context is strong enough to avoid major confusion.

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