UK Data: Web reader

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

With no annotations, the description does disclose the return shape (title, description, links, main content) and a real operational trait: a cost of 2 credits. It says nothing about JS-rendered pages, truncation, non-HTML content, rate limits, or failure modes, leaving meaningful behavioral gaps for a network-fetch tool.

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?

A single front-loaded sentence stating action, output and cost, with the credit price parenthesised at the end where it does not obstruct scanning. Nothing is redundant.

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 3-parameter fetch tool with no annotations and no output schema, the description covers output shape and cost but not truncation behaviour, handling of non-HTML targets, or error conditions. Adequate to call correctly in the common case, incomplete at the edges.

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 the schema already documents url, format and maxChars. The description only echoes the format choice (markdown vs plain text); it adds no guidance on choosing maxChars values or on what happens when content exceeds it. Baseline 3 applies.

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?

"Fetch a public web page and return its main content as markdown (or plain text)" gives a specific verb (fetch) and resource (web page) plus the returned representation. It does not distinguish itself from near-neighbours such as govuk_page, rss_read or pdf_to_text, so an agent must infer applicability rather than being told.

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 only scoping signal is the word "public", which implies pages behind auth or paywalls are out of scope. There is no statement of when to prefer this over siblings like wikipedia_summary, govuk_page or rss_read, and no exclusions or prerequisites.

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