references

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

With no annotations, the description carries the full burden, and it discloses meaningful behavior: which engine answers (cross-file index vs single-file language server), that results are scoped to the file's own root with separate WEBNAV_MCP_ROOTS, and the fallback when the scoped index has no hits. It omits any note on read-only semantics or result/pagination behavior beyond what the output schema covers.

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?

Purpose is front-loaded in the first sentence, with positional semantics and the CSS/HTML edge case following in a logical order. The middle paragraph is dense but each clause conveys usable information; no 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?

An output schema exists, so return-value explanation is unnecessary, and the description covers position semantics, the CSS/HTML token edge case, and root scoping. The one meaningful omission is what 'include_declaration' does, which affects results for a 4-parameter 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 must compensate; it does a strong job on the two error-prone parameters, specifying 1-indexing and UTF-16 offset semantics for 'column' (leading tab = one character). It leaves 'include_declaration' (default true) and 'file_path' unexplained, which is a notable gap for a result-shaping boolean.

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: 'Find all usages of the symbol at a position across the workspace.' This cleanly distinguishes it from the sibling 'definition' (goto-definition) and 'hover' (type info) without the agent needing to inspect either schema. Scope ('across the workspace') is explicit.

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?

Usage is implied by requiring a position (line/column) and by the CSS/HTML special-case paragraph, which routes to the cross-file index. However, there is no explicit when-to-use vs 'definition'/'search_symbol', and no stated prerequisites or exclusions for the normal language-server path.

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