add_pcg_graph_parameter

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

Annotations already declare non-read-only, idempotent, non-destructive, but the description adds real context beyond them: it explains the idempotency semantics ('already_existed when the name is taken'), warns about the side effect of editing a library asset, and supplies the return shape in the absence of an output schema.

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?

Front-loaded with what it does, followed by idempotency, the ownership caveat, sibling routing, and returns. Every sentence carries distinct information and no line 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?

No output schema exists, so the description correctly carries the return shape. For a 3-required-param mutation tool with annotations, all an agent needs to call it correctly and understand consequences is present.

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 100%, so the baseline is 3. The description nonetheless adds meaning: it enumerates the valid 'type' values in prose and clarifies name-collision behavior for the 'name' parameter, going slightly beyond 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?

States a specific verb and resource ('Expose a tunable on a PCG graph') plus the supported types, and explicitly distinguishes itself from both siblings (set_pcg_graph_parameter for values, get_pcg_graph_parameters for listing). An agent can route among the three without opening any schema.

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?

Gives the use case (drive density/radius/toggle from outside instead of welding into a node), names the alternatives and their roles, and adds an exclusion ('Only worth doing on graphs you own -- adding one to a library graph means editing that asset'). This is explicit when/when-not/alternatives guidance.

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