update_identity

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation risk is signposted. The description adds non-obvious behavior beyond that: a dual list/update mode triggered by omitting section/content, and an immutability rule for IDENTITY.md that constrains where writes may land. It still doesn't spell out that replace destroys existing section content or any permission requirements.

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?

Three tight sentences, each carrying distinct information (purpose/granularity, list mode, immutability constraint), with the core purpose front-loaded and no filler.

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 destructive write tool with destructiveHint already declared and no output schema, the description covers scope, targeting granularity, list mode, and the immutability boundary. It leaves minor gaps around failure behavior and permissions, but an agent has enough to invoke it correctly.

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 100%, so the baseline is 3. The description adds cross-parameter semantics the schema documents only per-field: omitting both `section` and `content` switches the tool into a listing mode, and it clarifies the file scope relative to the immutable IDENTITY.md.

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 names a specific verb and resource (update self-model/preferences) plus the granularity of the edit (H2 sections in identity files), which is far more precise than the sibling `update`. It does not explicitly name a sibling tool to contrast with, so it falls short of a 5.

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?

It gives an explicit operational condition ("Call without section/content to list available sections") and an explicit exclusion ("IDENTITY.md ... is immutable — only self-model and preferences can be edited"). No alternative sibling tool is named, but the when-to-use and when-not-to-use guidance is concrete.

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