read_scene

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

With no annotations, the description carries the full burden and does well: it discloses the size/performance characteristic ('thousands of elements'), the returned artifact (on-disk path), and a mutation risk with a mitigation ('take a snapshot first'). It stops short of stating that the call itself is a pure read or describing pagination/output shape, so not fully complete, but materially richer than the structured data.

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?

Three sentences, each doing distinct work: return content, alternative routing, and the edit/snapshot caveat. Front-loaded with the core return value, though the opening sentence is a fragment and could be tightened 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?

No output schema exists, but the description states what comes back (full scene plus file path) and warns about volume, which is what an agent needs. The remaining gap is that it never explicitly confirms the call is side-effect-free, which matters given the absence of annotations.

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 parameters (scene and includeFiles) are already documented in the schema, including the base64/megabyte rationale for includeFiles. The description adds no parameter-level syntax or format detail beyond that, so baseline 3 applies.

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?

Names a specific operation and resource ('the whole scene exactly as stored, plus the path to the .excalidraw file on disk'), and explicitly distinguishes itself from the describe_scene and read_elements siblings by framing them as the lighter-weight alternatives. An agent can tell it apart 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 explicit when-to-use guidance ('prefer describe_scene or read_elements unless you genuinely need everything'), names the condition that selects those alternatives (large scenes), and adds a safe-use rule ('take a snapshot first if you use it') for out-of-band editing. Both the selection path and the safety caveat are spelled out.

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