seo_page_speed

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively communicates this is a read-only measurement operation (no side effects implied), and lists the metrics and outputs including render-blocking analysis. However, it doesn't state anything about rate limits, whether the tool makes HTTP requests to the target URL, timeouts, or whether certain page characteristics would fail. It adds reasonable value but has gaps.

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 two sentences and reasonably efficient. The first sentence lists concrete metrics; the second adds a value-add about render-blocking and optimization detection. No wasted words, but the front-loading is good. It's slightly dense but acceptable for the informational value delivered.

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 single-parameter measurement tool, the description is reasonably complete. It lists what metrics are measured and what optimizations are identified. However, it doesn't describe the output format, units, or whether results are comparable across runs. With no output schema and no annotations, the description could be more complete about what a successful result contains (e.g., numeric values, units like seconds/bytes). Mild gaps exist.

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 the single parameter (url) is fully documented in the schema. The description adds 'Full URL of the page to measure' context via the schema. For a single-parameter tool, the description's mention of what specific metrics are measured adds useful context about what the url parameter's measurement entails, exceeding the bare schema requirements. Baseline 3 applies with 100% coverage, and the described metrics add mild additional value.

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 clearly states the tool measures page speed metrics with a specific verb ('Measure') and names specific resources ('Time to First Byte, total load time, HTML size, resource counts'). It identifies distinct capabilities (render-blocking resources, missing optimizations) that distinguish it from sibling SEO analysis tools. It doesn't name a sibling explicitly, but the purpose is well-scoped to page speed specifically.

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 provides no clear guidance on when to use this tool versus alternatives like seo_meta_analyze, seo_heading_check, or seo_keyword_density. It doesn't state exclusions, prerequisites (e.g., URL must be publicly accessible), or scenarios where it's preferred. The context is only implied by the general domain of SEO analysis shared across siblings.

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