Retrieve pets from an API, filtering by kind (cat, dog, bird) and limiting the number of results for targeted responses.
[GET] List all pets
| Name | Required | Description | Default |
|---|---|---|---|
| kind | No | Filter by kind | |
| limit | No | How many pets to return |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description adds only the '[GET]' method and list scope. It does't disclose pagination/default limit/response shape or filtering behavior, so contextual transparency is thin.
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?
One short sentence with no filler, method prefix ('[GET]') front-loaded. Every token earns its place; it is appropriately sized for a simple list endpoint.
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 read-only list with two optional params and no output schema, the description is mostly sufficient to invoke it. However, it leaves ambiguity about whether 'all' is exhaustive or paginated, and gives no hint of the return shape ā a real but minor gap.
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%, and both parameters already have meaningful descriptions ('Filter by kind', 'How many pets to return'). The description adds nothing beyond the schema, so the baseline of 3 is appropriate.
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 all pets'), making the operation clear. It distinguishes from sibling get_pet (singular object vs. collection) and other siblings by resource/scope, though it doesn't explicitly name them.
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?
No explicit when-to-use or alternative routing. The word 'all' implies collection-level fetching, and siblings like get_pet imply single-item lookup, but the description leaves the choice to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.