Retrieve a cat image mapped to any HTTP status code from http.cat without making a network call, useful for illustrating API errors and responses.
Get a cat image for any HTTP status code from http.cat (no network call).
| Name | Required | Description | Default |
|---|---|---|---|
| status_code | No | HTTP status code (e.g. 200, 404, 500). |
Changes observed during successful MCP inspections.
v0.1.11Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, so the safety profile is covered. The description adds that it involves no network call, which is genuinely useful for an agent deciding on latency/reliability, but it never says what actually comes back (an image URL vs image bytes), and 'no network call' sits slightly awkwardly with openWorldHint=true.
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, front-loaded with the verb and resource, with the distinguishing qualifier and the no-network trait appended efficiently. Nothing wasted.
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 trivial one-parameter tool this is nearly sufficient, but with no output schema the description should clarify whether it returns a URL or raw image data; that ambiguity is the main remaining 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 coverage is 100% with a single, well-documented parameter (status_code with examples), so the schema does the heavy lifting. The description's 'any HTTP status code' reinforces the intended range (including non-standard codes) but adds little beyond the schema.
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 ('Get a cat image') plus a distinguishing scope ('for any HTTP status code from http.cat'), which separates it from the many other cat-image siblings such as cat_api_random_image or cataas_random_cat without naming 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?
Usage is only implied: an agent can infer you use it when you need a cat image keyed to an HTTP status code. There is no explicit statement of when to prefer this over the other cat image tools, nor any prerequisites or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.