Open project

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

Annotations already declare idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds genuinely new context the annotations cannot: this is a global state change that redirects every other tool's default, and it returns a short overview plus next steps rather than the full digest. It does not discuss the one-way format upgrade risk that allow_format_upgrade implies.

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?

The core behavioral claim is front-loaded in the first sentence, followed by path formats, the per-call distinction, and a single illustrative example. Every sentence earns its place, though the parenthetical about project_summary and the example could be trimmed slightly.

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 no output schema, the description correctly summarizes the return value ('short overview + next steps') and redirects to project_summary for detail. For a 2-parameter tool with 50% schema coverage and existing annotations, this is nearly complete; only the format-upgrade caveat is missing.

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 50%, and the description compensates well for the undocumented `path` by listing accepted forms (project folder, .kicad_pro, .kicad_sch, .kicad_pcb) plus a concrete example value. The second parameter's meaning is carried by its own schema description, so nothing critical is left unstated.

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 pairs a specific verb and effect: 'Make an existing KiCad project the active one (all other tools then default to it)'. It then disambiguates from the per-call `project` argument on other tools and names project_summary as the fuller digest, so an agent can tell it apart from siblings without opening schemas.

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?

It clearly states the context that selects this tool (switching the persistent active project) and, crucially, clarifies that a `project` argument elsewhere is call-scoped while project_open is what actually changes state. It does not explicitly say when not to use it (e.g. project_create for new projects), but 'existing' implies the boundary.

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