fetch_files

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

With destructiveHint=true and openWorldHint=true already declared, the description still earns credit by naming the mechanics (tar over SSH), the retry behavior, and the concrete destructive consequence ("overwrites files of the same name"). It stops short of disclosing auth/login prerequisites for `host`, which matters given the `start_login` sibling.

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 compact sentences, front-loaded with the core action and scope, with parentheticals carrying secondary constraints. No sentence is filler.

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 transfer tool with no output schema and zero schema coverage, the description covers mechanics, overwrite hazard, retries, and the size cap well. It leaves open what the call returns (copied paths? byte counts?) and the host-omitted behavior, which an agent would still have to discover.

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 0%, so the description carries the burden and does reasonably: `max_mb` is given meaning as a refusal threshold, `local_dir` as the destination, and `host` is cross-referenced to `push_files`. It does not explain what a null/omitted `host` means (default null in schema) or the units/naming of remote vs local, leaving one real gap.

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 (copy) and resource (file or directory) with explicit directionality: from the cluster into `local_dir` on `host`. The reference to `push_files` plus the directional framing lets an agent distinguish it from the reverse-transfer sibling without opening either 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?

The parenthetical "fetch subdirectories of big results" is genuine routing advice for the max_mb failure case, but there is no explicit statement of when to pick this over `run_command` or how it relates to the login/cluster siblings. Usage is implied by "from the cluster" rather than spelled out.

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