Trace TIA Symbol

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

Annotations declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, which is an unusual combination; the description usefully explains it by stating the cache is rebuilt automatically when the export signature changes. That reconciles the apparent contradiction and tells the agent the tool may write to a cache but is safe to repeat. It still does not describe result size, pagination, or what happens on a cache-rebuild failure.

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, front-loaded with the capability and followed by the cache-rebuild caveat. No filler or repetition. The first sentence is a dense enumeration, but every item is load-bearing.

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 five-parameter tool with zero schema description coverage, no output schema, and a non-read-only annotation, the description is thin. The agent knows what the tool conceptually does but not how to set match, limit, autoBuild, or what exportDir should point to, nor what the result looks like.

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 0% across five parameters, so the description carries the full burden of explaining exportDir, query, match, limit, and autoBuild. It explains none of them: match's exact/suffix/contains modes, the 1-500 limit bound, and what autoBuild=false implies are all undocumented. The only indirect signal is that "symbol" is what query presumably searches for.

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 uses a concrete verb ("Find") with a specific set of resources: symbol definitions, writers, readers, and direct upstream/downstream flows, scoped to SCL, LAD/FBD calls, and GRAPH actions. That is enough for an agent to know exactly what is returned. It stops short of naming which sibling to use instead (e.g. tia_trace_data_flow for deeper flow analysis), so it is clear but not differentiated.

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 only implied by the purpose statement: use it when you need to locate a symbol and its immediate references. There is no explicit when-to-use/when-not-to-use guidance and no mention of the trace-related alternatives in the sibling set. An agent must infer the routing decision from the wording alone.

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