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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is fully covered without the description. The description adds one useful behavioral fact — that search reaches into full source code, implying broad match scope — but says nothing about result ordering, result caps, or pagination for what could be a large result set.

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?

Two sentences, both front-loaded: the mechanism first, then the applicability. The example list is compact and functional rather than 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?

With one fully documented parameter, rich annotations, and no output schema, the description covers nearly everything an agent needs to invoke it correctly. The only real gap is what a search returns in shape and volume, which matters because matching against full source code could produce large results.

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 goes beyond the schema by specifying which fields the query string is matched against (titles, descriptions, tags, full source code) — that is real semantics about how the input is interpreted. It stops short of describing matching rules (substring vs fuzzy, case sensitivity, multi-word behavior).

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 skills') plus the exact fields matched (titles, descriptions, tags, full source code), which tells an agent this is a keyword search rather than a lookup. It does not explicitly contrast itself with the sibling listSkills or getSkill, so the boundary must be inferred.

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?

'Use for any iOS, SwiftUI, or backend topic' gives clear positive usage context, reinforced by a concrete keyword list (subscription, authentication, camera, paywall, infrastructure) that doubles as example use cases. There is no when-not guidance and no pointer to listSkills or getSkill as alternatives.

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