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

With no annotations, the description must carry the burden, and it does explicitly disclose the key behavioral trait that the check involves no disk access. However, it does not explain what 'safe' means (e.g., traversal, absolute paths, null bytes), what the function returns, or whether it can throw. This is a useful but partial disclosure.

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?

Two short sentences, no filler, and the most important operational constraint ('No disk access') is placed in its own sentence. It is arguably too terse for the tool's complexity, but as structure it is efficient and front-loaded.

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?

The tool has 9 parameters, no annotations, and no output schema, yet the description only states the general purpose and the no-I/O property. There is no return contract, no safety-criteria definition, and no guidance connecting the many parameters to the check. This is significantly incomplete for an agent to invoke confidently.

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%, so every one of the 9 parameters already has its own description; the tool description adds no parameter-level semantics. Baseline 3 is appropriate because the description does not need to compensate, but it also contributes no extra param context.

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?

Clearly names the operation ('Check') and the resource ('a path') and adds a safety criterion ('looks safe'). The phrase 'No disk access' helps differentiate it from filesystem-touching checks and sibling URL checkers, though it does not explicitly contrast with 'browser-url-ok' or 'playwright-url-ok'.

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?

The 'No disk access' clause gives a clear context signal: this is a non-I/O validation, so it can be called when only path shape matters. But it does not state when to prefer it over alternatives, nor provide any exclusions or explicit 'use this instead of X' guidance.

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