get_cache_file

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

Beyond readOnlyHint=true, it discloses the return shapes (printable text vs base64 bytes when download=true), the failure mode (404 if missing), and a security constraint (sensitive files refused when secret redaction is on). That is exactly the kind of context annotations cannot convey.

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 tightly packed sentences: identity and source of truth first, then return semantics, then error/security behavior, then the discovery pointer. No filler and nothing buried.

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 no output schema, the description still explains both return modes and the error case, and it names the prerequisite listing tool. For a five-parameter read-only fetcher, an agent has everything needed to invoke it correctly.

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 already documents download, service (omit for global), plugin, job_name and file_name, so the description's restatement of the identity tuple and base64 behavior adds little new meaning. Baseline 3 applies when the schema carries the parameter burden.

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 ("Read one job cache file") plus the exact identity tuple (service, plugin, job_name, file_name), and explicitly contrasts with list_cache_files. An agent can distinguish it from the sibling cache tools without opening the schema.

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?

Directs the agent to list_cache_files as the discovery step before calling this tool, which is the real prerequisite. It lacks an explicit when-not statement (e.g., use delete_cache_files to remove), but for a single-file reader there is little ambiguity about alternatives.

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