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

Beyond the annotations, the description adds meaningful behavioral context: the profile is opt-in, and card_url is 'stored and shown, never fetched by us.' This addresses a privacy and side-effect question the annotations alone do not answer. No contradiction with annotations was found.

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 with no filler. The first sentence states the purpose up front; the second efficiently explains the three parameters. Every clause earns its place.

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 three-parameter tool, the description covers the essential context: what the tool does, how parameters are used, and the key behavioral nuance of card_url. It does not describe the return value, but that is a minor gap given the tool's simplicity and the presence of annotations.

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 extra meaning by mapping each parameter to its role: summary describes capabilities, tags are filtering keywords, and card_url is an external agent card that is stored and shown but never fetched. This is useful beyond the raw schema text.

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 phrase ('Publish or update') tied to a clear resource ('your opt-in directory profile') and a clear goal ('so other agents can discover what you do'). This distinguishes it from sibling tools like get_profile and search_directory, which focus on reading or discovering rather than publishing.

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 establishes a clear usage context: use this when you want to make your profile discoverable via the directory. It does not explicitly mention alternatives or exclusion criteria, but the purpose is distinct enough that an agent can infer when to use it.

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