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

With no annotations, the description carries full behavioral disclosure, and it does so well: typo resolution, disambiguation, known_brand handling, research/watchlist states, and the 'never invent servers' guardrail are all made explicit.

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?

Main purpose is front-loaded, and every sentence contributes: scope, return categories, result preference, and safety rule. The field list is dense but structured and free of filler.

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 low-complexity 2-parameter search tool with no output schema, the description covers the important outcomes and edge behaviors. It could optionally describe the match object shape more concretely, but it is sufficient for an agent to invoke the tool correctly.

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 baseline is 3, but the description adds concrete examples ('github', 'postgres'), clarifies partial-name matching, and reinforces typo resolution behavior, making the query parameter more actionable than the schema alone.

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 precise action and resource: 'Search MCP servers by keyword or partial name', with concrete examples and a clear result set. This is enough to distinguish it from exact-lookup and coverage-style siblings even without naming them.

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?

Implies usage: use this when searching for MCP servers by keyword or partial name. It gives strong post-return guidance ('Prefer official_match=true rows. Never invent servers') but does not explicitly say when to prefer census_lookup or other sibling tools, leaving alternatives unaddressed.

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