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

Goes well beyond the annotations with the prompt-injection warning about untrusted visitor-typed fields, the privacy constraint on sharing third-party personal data, and the free-plan lock once the card passes 50 views. These are exactly the operational traits an agent cannot infer from readOnlyHint/idempotentHint.

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?

Front-loaded with the verb and resource, then clearly partitioned into SECURITY and PRIVACY blocks. Slightly verbose in restating read-only twice ('Read-only' plus 'cannot create, edit or delete'), but every part carries actionable 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?

With an output schema and full annotations available, the description fills the remaining gaps – when leads exist, untrusted-content handling, privacy limits, and plan-based data locking. Nothing needed to call or safely interpret this tool is missing.

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 description coverage is 100%, with limit, offset, apiKey and a status enum all documented inline, so the baseline is 3. The description only echoes the status filter and adds ordering ('newest first'), which is not parameter syntax, so no real lift above baseline.

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?

States a specific verb and resource ('List the contact form submissions (leads)') plus scope ('on this account's card'), ordering ('newest first') and filterability. It also distinguishes itself from sibling create_or_update_card by naming the tool that must have been used for leads to exist at all.

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?

Gives a clear precondition for use ('Leads only exist if lead capture is on (see create_or_update_card)') and an explicit exclusion ('cannot create, edit or delete leads'). It does not discuss routing against other read siblings (get_card, get_analytics), but for a tool with no true read-alternative the guidance is solid.

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