set_test_run

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

Annotations already declare readOnlyHint=false, destructiveHint=false and idempotentHint=true, so the safety profile is covered. The description adds the useful merge semantics ('only ... you pass change'), but calling it 'JSON Patch' is loose since the schema takes a plain object rather than an RFC 6902 patch array, which could mislead an agent, and no return behavior or permission requirements are described.

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?

One compact sentence that front-loads the verb and the partial-update semantics with no filler. It is efficient, though the parenthetical '(JSON Patch)' is arguably noise given the actual payload shape.

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 a small 4-parameter mutation with no output schema this covers the essentials: what it mutates and that changes are partial. Gaps remain on what the response contains, whether tags are replaced versus merged (only the schema says 'Replaces all tags'), and permission expectations.

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 only 50%: 'id' and 'tags' are documented in the schema while 'name' and 'description' are bare. The description compensates partially by naming those fields and clarifying that omitted fields are left untouched, but it adds no format, validation or replacement details beyond the schema's note that tags are replaced wholesale.

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 gives a specific verb phrase and resource: 'Partially update a test run', and adds the scope qualifier that only name, description and tags are touched. That distinguishes it from mutation siblings like create_test_run, delete_test_run or complete_test_run, though it never names those siblings explicitly.

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 word 'partially' and the field list imply the intended use case (edit a few metadata fields without replacing the run), but there is no explicit when-to-use or when-not guidance and no pointer to an alternative tool for full replacement or state changes.

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