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

Annotations only declare readOnlyHint=true and openWorldHint=false; the description goes further by disclosing a paid call (0.05 USDC on Base), that it does not sign or charge, and that it returns the canonical endpoint plus payment instructions. That is meaningful context an agent cannot get from annotations and is consistent with readOnlyHint. It stops short of describing failure modes or what happens if payment is declined.

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?

The description is short and front-loads the core action, but the sentences are choppy and out of order: 'Measures sampled ink geometry' arrives after the return-value sentence and reads as an afterthought. The 'does not perform analysis, sign or charge' clause is efficient, but the opening 'Check whether...' followed by 'does not perform analysis' costs a re-read.

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 usefully states what is returned (canonical endpoint, supplied input, payment instructions), which is a real strength. But for a 5-parameter tool with a nested object and zero schema coverage, the input side is severely under-explained, and there is no mention of what the downstream endpoint expects. Complete on the output/payment side, incomplete on the input side.

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% across 5 parameters, including a nested 'conditions' object, so the description carries the full burden and does not meet it. 'Measures sampled ink geometry' loosely hints that rows are sample points, but nothing explains the format of 'rows', the units or bounds rationale for widthMm/heightMm, the accepted 'method' values, or the structure of 'conditions'. An agent would have to guess at the input contract.

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 names a specific verb and resource (prepare a paid HTTP request for a print-check geometry evaluation) and scopes it with 'Not a PDF/CDR importer', which separates it from importer-type tools. It also clarifies it 'does not perform analysis', resolving the tension with the opening 'Check whether sampled details are too fine'. It does not explicitly distinguish itself from the many prepare_* siblings (prepare_preflight, prepare_small_features), which keeps it below a 5.

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 negative guidance ('Not a PDF/CDR importer') and the note that it prepares rather than analyzes imply the usage context. However, there is no explicit statement of when to choose this over prepare_small_features or prepare_preflight, which are the closest siblings given the 'too fine' phrasing. Usage is inferable but not stated.

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