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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: 'No API key required' addresses authentication, and the mention of 'per-endpoint pricing (including metered bands)' and 'cache TTL' tells the agent what to expect in return. This exceeds the baseline set by annotations alone.

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 compact: four sentences, each earning its place. The primary action and return contract are front-loaded, followed by query modes, filters, and the auth note. There is no filler or redundancy with the schema.

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?

Despite having no output schema, the description enumerates what the returned full parameter contract contains, and the schema richly documents all six optional parameters including pagination behavior. The combination of description, schema, and annotations gives an agent everything needed to call this tool correctly for reference lookups and cross-platform searches.

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 each parameter already has a detailed description in the schema. The main description mostly restates the schema's guidance (platform vs. search, method and maxCost filters) without adding new parameter-level meaning. The '65 platforms / 572 endpoints' statistic adds scope context but not semantic detail, so a baseline of 3 is appropriate.

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 specific verb and resource: 'List endpoints with their full parameter contract.' It enumerates exactly what the contract includes (types, ranges, enums, couplings, pricing) and distinguishes this from siblings like socialcrawl_list_platforms by focusing on endpoints rather than platforms. No ambiguity about what the tool does.

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 clearly states the primary query modes: 'Pass a platform for that platform's reference, or a search term to find an endpoint across all 65 platforms / 572 endpoints' and 'Filter with method and maxCost.' This provides clear context for use, though it does not explicitly name sibling alternatives or state when not to use this tool.

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