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

Annotations declare readOnlyHint=false and destructiveHint=true, and the description substantiates those by describing the write into the user's Sheets. It adds context annotations do not carry: the shared-seed execution guarantee ('differences are the scenarios and not the dice'), the exact artifacts produced (comparison table plus trajectory chart vs. data tabs), and the daily publish quota. No contradiction with annotations.

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?

Four sentences with zero filler. The core purpose is front-loaded in sentence one, differentiation in sentence two, behavioral detail in sentence three, and return value plus quota in sentence four. Every sentence earns its place.

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 2-parameter tool with fully documented schema and no output schema, the description covers everything needed to call it correctly: the return value (sheet URL), side effects, quota implications, and the seed-sharing behavior that affects how the output should be interpreted. Nothing an agent needs 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 100% — both id and scenarios carry descriptions, with scenarios including a concrete JSON example. The description adds no parameter-specific syntax or format guidance beyond the schema, so the baseline 3 applies; the seed-sharing note is behavioral context rather than parameter semantics.

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 opens with a specific verb and resource: 'Publish a multi-scenario comparison into the signed-in user's Google Sheets.' It then explicitly positions itself against siblings ('sim_compare's export, the counterpart of sim_publish for a single scenario'), so an agent can distinguish it from both sim_publish and sim_compare without opening their 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?

The description names sim_publish as the single-scenario alternative, giving the agent an explicit routing condition: multi-scenario comparisons go here, single scenarios go to sim_publish. It also ties itself to sim_compare's shared-seed semantics, clarifying the relationship between the analysis tool and its export.

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