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

Annotations already declare destructiveHint=true and idempotentHint=true, so the description doesn't need to restate safety. It adds value by listing the specific updatable fields, which is not in the schema. However, it doesn't explicitly state that it's a partial patch (only provided fields change), though the parameter name 'patch' implies it. This is adequate given the annotations.

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 a single, front-loaded sentence that immediately states the action and scope. There is no wasted wording, and the key information (verb, resource, fields) is delivered efficiently.

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 simple update tool with only two parameters and no output schema, the description covers the essential behavior. It doesn't explain return values or prerequisites, but annotations cover safety and the patch semantics are implied by the parameter name. The tool is moderately complex, and the description is sufficiently complete.

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 schema only describes patch as 'Fields to update.' with 50% coverage (project_uuid has no description). The description compensates by enumerating the exact fields (display_name, description, show_public, live_url), giving agents concrete knowledge of what can be patched. This goes beyond the schema and improves parameter understanding.

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 uses a specific verb ('Update') and names the exact resource ('project') plus enumerates the metadata fields (display_name, description, show_public, live_url). This clearly differentiates it from sibling tools like build_create_project and build_replace_project, which are distinct operations.

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 implies this tool is for modifying existing project metadata, but it does not explicitly state when to use it over alternatives like build_replace_project or build_create_project. The context is clear from the verb and fields, but no exclusions or alternative recommendations are given.

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