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

With no annotations, the description carries the full behavioral burden and does disclose meaningful traits: cost per mode ($0.02 for ?id=, $0.05 otherwise), the 402 for unpaid requests, and that a valid X-PAYMENT header yields JSON. It stops short of describing the returned JSON structure, but the payment/error behavior is genuinely transparent.

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?

It is a single dense run-on that mixes price, payment mechanics, and access modes, and the trailing fragment 'Not a new SKU.' is confusing rather than informative. Still, the URL and core modes are front-loaded and there is no padding sentence.

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 5-parameter paid fetch tool with no output schema and no annotations, the description covers payment mechanics and access modes adequately. But with no output schema it should say more about what the JSON contains than simply 'returns JSON', so it is only marginally complete.

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 already documents itself, and the description largely repeats that information (id vs since/before, page as newest-first). It adds the per-mode pricing association but no syntax or format detail beyond the schema.

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?

The description does convey that this retrieves MSHA Fatality Investigation Final Report text, and distinguishes the ?id= single-document mode from the chunked modes. However, the purpose is buried under pricing boilerplate and the cryptic 'Not a new SKU' phrasing, and it never differentiates itself from the many sibling report/decision tools.

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?

It does describe the invocation modes: plain GET for the newest chunk, ?before for older, ?since for newer-than-watermark, ?id= for one official text. That is real usage guidance, but there is no when-to-use vs sibling tools and no prerequisites beyond the payment note.

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