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

Annotations already declare readOnlyHint=true, and the description complements this by explaining the data is aggregate measurement-corpus data and that 'a thin result means the engines rarely cite it.' It also clarifies what the 'profile' contains, including the caveat that the listing page is included only 'where our crawler found one.' This adds interpretive context beyond the read-only annotation without contradicting it.

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 front-loads the core idea—'A profile of any domain the answer engines cite'—then uses a colon and parentheticals to compactly enumerate result contents. The second sentence adds measurement-context and result interpretation, earning its place. Slightly long and the title is diluted ('What a cited source is and how to get on it'), but the body is dense rather than padded.

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 one required parameter and readOnlyHint=true, the description covers what the agent gets back (frequency, count coverage, homepage title/description, co-read pack, listing page) and how to interpret sparse results. No output schema exists, so the inline enumeration is the main return-value documentation and it is adequate. Missing explicit when-to-use guidance against siblings, but the tool is simple enough that the gap is not severe.

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%, and the schema already defines `source` as 'The source domain, e.g. canstar.com.au or yelp.com.' The description's phrase 'any domain the answer engines cite' reinforces that the parameter is a citing domain, but it adds no format, normalization, or edge-case semantics beyond the schema. Baseline 3 applies because the schema carries the parameter documentation.

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 opens with 'A profile of any domain the answer engines cite' and then enumerates specific content categories (frequency, business/category coverage, homepage title/description, o-read pack, listing page), making the tool's purpose concrete. It doesn't explicitly contrast with sibling tools like get_citation_sources, but the resource (a single domain's profile) and output categories are unambiguous. The verbose title adds little, but the description body compensates.

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 description implies this tool is for inspecting one cited domain's profile, but it never states when to choose it over siblings like get_citation_sources or get_visibility. There is no when-not-to-use guidance or alternative routing. An agent must infer the use case from the data-listing alone.

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