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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=true, idempotentHint=false), and the description usefully adds patch semantics with "Fields left out stay as they are" plus the return value. However, it never explains what makes the operation destructive (e.g., body/title being overwritten) or what permissions are required, so an agent cannot anticipate the destructive risk the annotations flag.

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 short fragments, front-loaded with the action and followed by the key partial-update rule and return value; nothing is padded. "Returns: The pin." is minimal but carries useful information given no output schema.

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?

Given 100% schema coverage and full annotation coverage, the description's burden is modest, and it covers action, partial-update behavior, and return value. It is still thin on what a destructive pin edit can overwrite and on the campaign/permission context, which matters for an 8-parameter mutation.

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%, so all 8 parameters are already documented with meaning (x/y coordinates, pin id, campaign slug-or-id, isPrivate). The description only adds the partially-applied semantics of omitted fields, which is genuinely useful but thin given full schema coverage.

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?

"Move a pin or change what it says" gives a specific verb and resource and implies the update operation as distinct from create_pin/list_pins in the sibling set. It stops short of naming those siblings explicitly, so differentiation is inferred rather than stated.

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?

There is no explicit when-to-use guidance, no mention of prerequisites (campaign membership, pin ownership), and no routing to alternatives such as create_pin or update_map. The only usage-adjacent signal is the implicit patch semantics, which is behavioral rather than directive.

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