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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower; the description still adds the return shape (text plus archived replay URL) and the truncation behavior. It does not contradict any annotation.

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 dense sentences with no filler, front-loading what is read before describing inputs, return value, and use case. Slightly long but every clause carries information.

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 compensates by stating exactly what comes back (plain text, optionally truncated, plus replay URL). For a single-capture read tool with 100% schema coverage and full annotations, nothing an agent needs is missing.

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 baseline is 3, but the description adds provenance meaning beyond the schema: the timestamp is the value returned by arquivo_search_pages or arquivo_url_history, and max_chars causes truncation of the returned text. That provenance link is what an agent needs to chain the tools.

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?

Specific verb ('Read the extracted plain text') and resource ('one archived page capture'), with an explicit scope constraint ('HTML stripped, as the archive indexed it'). It is clearly distinguishable from arquivo_search_pages and arquivo_url_history, which it identifies as the producers of its inputs.

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?

Gives clear usage context ('quote or summarise what a Portuguese page said on a given date without fetching the archived HTML') and names the sibling tools that supply the url/timestamp pair. It lacks an explicit when-not condition, but the intended scenario is unambiguous.

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