Map a file's symbols with signatures and line ranges, or a directory's files with symbol counts, so agents can inspect structure before reading full files and reduce context tokens.
Symbol map of a file (signatures + line ranges) or dir (files with symbol counts). Use before reading files.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | file or dir; relative to first root | |
| depth | No | nesting depth (file) / dir depth |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, so the safety profile is covered. The description additively discloses the shape of what comes back (signatures and line ranges, or files with symbol counts), which is real value, but says nothing about ordering, truncation, or behavior on paths that don't exist.
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 compact sentences with no filler, and the definitional clause comes before the workflow hint. It is slightly telegraphic (parenthetical fragments rather than full clauses), but nothing is wasted.
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 simple two-parameter read tool with full schema coverage and a readOnly annotation, the basics are covered and the return shape is sketched. However, with no output schema, the description could have said more about what a consumer does with the symbol map (e.g., line ranges enable targeted reads).
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 100% – both 'path' and 'depth' are documented in the schema itself. The description's '(file) / dir' phrasing echoes the path semantics without adding format or boundary detail beyond what the schema provides, so baseline 3 applies.
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 concrete resource and operation: a symbol map, with the two output shapes parenthesized (file = signatures + line ranges, dir = files with symbol counts). That distinguishes it from read_symbol, which returns actual source, though no sibling is named explicitly.
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 before reading files' gives an explicit sequencing instruction, which is genuine when-to-use guidance that points toward read_symbol without naming it. There are no exclusions or explicit alternatives, which keeps it from a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.