capability_search

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

With no annotations, the description carries the full burden. It discloses the source (official MCP Registry), the return fields (name, description, version, packages with npm/pypi identifiers), and the downstream handoff, which is genuinely useful. It omits that this is a read-only lookup, whether queries are fuzzy or exact, and any rate limit or empty-result behavior.

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?

Three sentences with no filler, front-loaded with the action and source before the return shape and handoff. Every sentence adds a distinct piece of information.

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?

An output schema exists, so return values are partly covered for free, and the description additionally names the key fields and the install handoff. The remaining gap is the undocumented limit parameter and unspecified behavior for zero results, which is minor for a two-parameter search tool.

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 0%, so the description has to compensate. It implies query is a string used to match servers and hints the returned name is what feeds capability_add, but the limit parameter (default 5) is never mentioned in either the schema or the description, leaving one of two parameters undocumented.

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 gives a specific verb and resource ('Search the official MCP Registry for installable MCP servers') plus the shape of the result, which no sibling provides. It is clearly distinct from capability_add/consider/verify/list/remove, and it even routes the agent forward to capability_add.

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?

It states the context of use (finding installable servers in the official registry) and names the next step explicitly: 'Pass a server's name to capability_add to install it.' It does not say when to prefer this over siblings like capability_consider or capability_list, so an exclusion clause is missing.

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