figma_spec

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

Annotations already establish readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful beyond-annotation behavior: a 'never invent' no-hallucination promise and batching behind a single approval. It does not mention output shape or errors, but the read-only nature is well covered.

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 entire description is two short sentences with zero filler. It front-loads the core promise ('Exact layer facts; never invent') and follows with a specific, actionable batching note. Every word 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?

This is a complex tool: 9 optional parameters, anyOf constraints, no output schema, and 11 sibling tools. Two brief sentences do not provide enough context for an agent to understand what 'spec' returns, how nodeId and nodeIds interact, or when to pick this over figma_inspect/reference. The schema fully covers parameter syntax, but not tool selection or output expectations.

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 the 9 parameters are already fully documented in the input schema. The description adds a small extra semantic around nodeIds — that batching 8 reads happens behind one approval — but it does not compensate for or clarify the other parameters, so the baseline of 3 is appropriate.

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 phrase 'Exact layer facts' clearly identifies the resource (layers) and the nature of the output (facts, not guesses), while 'never invent' signals a fidelity guarantee. It does not use an explicit verb like 'get' or 'return', and it does not explicitly distinguish itself from figma_inspect or figma_reference, so it stops short of a 5.

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 line 'nodeIds[] batches 8 reads behind one approval' gives actionable guidance to batch multiple reads for efficiency, which is genuinely useful. However, it never says when to choose figma_spec over sibling tools or when not to use it, so the guidance remains implied rather than explicit.

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