capability_upsert_self

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

Beyond the idempotentHint annotation, the description discloses a key behavioral trait: 'Only supplied fields are changed; omitted fields are preserved.' This is valuable, though it does not clarify the 'upsert' aspect (whether it also creates a profile if missing) or discuss edge cases like validation errors.

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 two sentences, front-loaded with the primary purpose in the first sentence and usage guidance in the second. Every sentence adds value, with no redundant or filler content.

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?

The description, combined with the existing output schema and annotations, provides sufficient context for selecting the tool and understanding its basic behavior. It names the alternative tool for a narrower use case and clarifies the partial-update semantics. A minor gap is the lack of mention of whether the tool creates a profile if absent, which could matter for the 'upsert' name.

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?

The description mentions high-level field categories ('skills, constraints, tool access, or capacity settings') that map to schema fields, and explains the partial-update filter behavior. However, it does not enumerate any parameter names or explain the nested skills structure, leaving the schema to carry the full burden for parameter details. With 0% schema coverage in the description, this is only partial compensation.

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 the verb 'partially update' and the resource 'this agent's capability profile in the active room,' giving a specific action and scope. It also distinguishes itself from a sibling tool by referencing capability_set_availability, which removes ambiguity about the tool's niche.

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?

Explicit guidance is provided: 'Use this for skills, constraints, tool access, or capacity settings; use capability_set_availability when only availability and optional current_load need to change.' This clearly states when to use the tool versus the alternative, and also implies when not to use it.

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