Update agent

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

Annotations already declare readOnly=false, destructive=false, idempotent=true, and openWorld=true, so the safety profile is covered. The description does add genuine behavioral value by clarifying merge/patch semantics (unspecified fields are preserved), which annotations alone do not convey. It stops short of stating permission requirements or what happens on invalid field names.

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, front-loaded with the verb and resource, with no filler. The second sentence is terse to the point of being slightly oblique ("supplied" implicitly means the keys present in agent_fields), but nothing is wasted.

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?

An output schema exists and annotations are rich, so return values and safety need no explanation. However, for a mutation tool with a nested free-form object parameter, the description does not explain how to construct agent_fields, whether unknown keys are rejected, or what happens to fields omitted vs. explicitly set to null.

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% and the agent_fields property enumerates all allowed field names, so the schema does the heavy lifting. The description's only parameter-adjacent contribution is reinforcing the partial-update behavior of agent_fields; it adds no format, type, or validation detail beyond the schema.

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 ("Update an agent"), which is unambiguous on its own and pairs with a title that says the same. It does not, however, distinguish itself from close siblings such as create_agent, deactivate_agent, or reactivate_agent, so an agent must rely on the name alone to disambiguate.

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?

"Only the supplied fields change" describes partial-update semantics rather than when to use this tool versus alternatives. There is no mention of prerequisites (e.g., needing an existing agent_id, permissions required), no exclusion guidance, and no pointer to get_agent or get_agent_fields for discovering valid field names before updating.

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