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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so safety is covered. The description adds useful context beyond the annotations by disclosing the return payload: 'ranked listings with public GitHub stars, launch date and listing URL', which matters because there is no output schema.

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?

Front-loaded with purpose and usage before the long kind glossary, and every sentence carries information. The trailing glossary is verbose but earns its place by disambiguating an enum that would otherwise be opaque.

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 10-parameter, filter-heavy search tool with no output schema, the description covers purpose, triggers, return shape and the most ambiguous enum. The remaining gap is that several numeric/temporal filters (limit, offset, launched, minStars) are left to their schema constraints alone.

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 only 30% across 10 parameters, so the description must compensate. It does so meaningfully for the key filter by defining every kind enum value (server/client/product/skill/plugin/rules/eval), which the raw enum list does not explain. However, sort, launched, minStars and verifiedOnly still receive no explanation here or in the schema.

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?

States a specific verb and resource ('Search RUAGENTIC listings by words, with optional filters') and clearly distinguishes itself from narrow siblings like get_listing, top_listings and new_listings by being keyword-driven with filters. An agent can identify the tool's role without opening the schema.

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 a concrete trigger: 'Use when someone asks for an MCP server, client, AI agent, skill, plugin, rules file or eval for a task, a product, a category or a platform.' This is clear usage context, though it never names an alternative tool or states when NOT to use it (e.g., for a single known listing, use get_listing).

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