Invoke CDN OpenAPI operation

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

Annotations already declare destructiveHint=true, readOnlyHint=false, openWorldHint=true, so the safety profile is covered structurally. The description adds real value beyond them: a 238-op allowlist, a hard reject on unknown paths, and a 'does not invent APIs' guarantee, which tells the agent it will fail rather than hallucinate a route.

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?

Four short clauses, zero filler, with the identity of the tool front-loaded and the routing caveat placed before the allowlist detail.

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 spec-passthrough tool with no output schema, the description supplies the key operational facts an agent needs: which spec, how many operations, that it is a fallback, and that invalid paths are rejected. Only body/query semantics remain thin, which is defensible when the OpenAPI document itself is the reference.

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 only 25%, so method/path are documented (and method has an enum) while body and query are not. The description compensates partially by constraining 'path' to the cdn-4.0.yml spec and mentioning template locations, but says nothing about how body or query values are interpreted for the 238 operations.

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 ('Call any path from CDN OpenAPI 4.181.3') and pins the exact API surface (napi.../cdn/4.0) with an operation count, so it is clearly distinguishable from the sibling invoke_* passthrough tools (storage/iaas/vod/live).

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?

Explicitly routes the agent: 'Prefer named CDN tools when available,' which tells it this is the fallback. It stops short of naming precisely when the escape hatch is unavoidable (i.e., no named tool covers the operation), but the preference ordering is stated plainly.

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