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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral context: the operation runs 'locally' with no network access, and it enumerates the specific facts that will be extracted, which matters because no output schema exists. It stops short of covering failure behavior for malformed or missing `.dsn` input.

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, no filler, and the parse target plus input sources are front-loaded before the extraction inventory. Every clause carries information an agent would otherwise have to guess.

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 two-parameter, read-only parser with no output schema, the description is close to complete: it discloses the return contents field-by-field, which substitutes for the missing output schema. The remaining omission is the requirement that one of the two optional source parameters actually be supplied, and what happens on parse failure.

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%, so both `dsn_text` and `project_path` are already documented in the schema, and the description only restates them as alternative sources. With zero required parameters, it does not clarify that at least one source must be provided, nor how conflicts between the two are resolved — the one piece of meaning that would have exceeded the schema.

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 pair ('Parse and analyze') bound to a precise resource ('Specctra `.dsn` PCB autorouter file'), and names the two input channels. The explicit file-format qualifier cleanly separates it from format-specific siblings such as analyze_kicad_pcb without needing to name them.

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 rather than stated: '(from `dsn_text` or `project_path`)' and 'locally' tell the agent this is an offline parse of an existing file, which rules out remote or generation workflows. There is no explicit when-to-use versus when-not guidance, no mention of which sibling to pick for other board formats, and no statement about precedence if both source parameters are supplied.

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