carrel_redact

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

With no annotations, the description carries the full behavioral burden; 'Never writes' is a valuable explicit disclosure of non-mutation that substitutes for destructiveHint=false. It stops there, though: nothing about invalid-regex handling, size limits, encoding, or whether the source file is guaranteed untouched beyond the one-word claim.

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 tight sentences, front-loaded with the action and immediately followed by the two constraints that matter (no writes, no PDFs). Nothing is wasted and nothing needs reordering.

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 five-parameter, single-required-arg tool with a fully documented schema and no output schema, the description covers the essentials: what it returns, that it does not write, and what input types are rejected. Only edge-case behavior (bad regexes, large files, encoding) is left implicit, which is a minor gap here.

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%, so every parameter including the builtin pattern list and custom regex array is already documented. The description adds no meaning beyond the schema — it never distinguishes builtin from pattern or explains how the default replacement character behaves.

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 (redact) on a specific resource (a text file's contents) and notes the result is returned rather than persisted. The text-file restriction plus the PDF exclusion makes the scope unambiguous, though it never names a sibling tool as an alternative.

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?

'PDFs must go through the CLI (carrel redact FILE.pdf -o OUT.pdf)' is an explicit exclusion that routes the agent elsewhere with a concrete command. However, there is no positive guidance on when to choose this over e.g. carrel_convert or carrel_search, so the picture is clear but not complete.

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