add_svg

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

With no annotations, the description carries the full burden. It does disclose two genuinely useful behaviors beyond the schema: how coordinates are interpreted with/without x_mm/y_mm, and that colliding ids are silently renamed. It omits whether the operation is additive, what 'show' does, and nothing about undo/reversibility or required document state.

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 tight sentences, front-loaded with the purpose, then the placement rules with a concrete numeric example, then the id-collision caveat. The example earns its place by making the coordinate contract unambiguous; there is no filler.

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 an 8-parameter mutation tool with no annotations and no output schema, the description covers the drawing and coordinate model well but leaves show, index, expected_revision, and the parent target's semantics unexplained. An agent could invoke it for the basic case but would be guessing on ordering and concurrency.

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 0% across 8 parameters, so the description must compensate. It does explain x_mm, y_mm, units and markup (via a concrete worked example), but index, show, and expected_revision receive no explanation at all, leaving the concurrency and ordering semantics undocumented.

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: drawing arbitrary content by writing SVG markup, with an enumeration of what can be drawn (shapes, lines, arrows, text, groups, gradients). This is far clearer than the vague sibling names (insert, text, structure), though it never explicitly says how it differs from those alternatives.

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?

Usage is implied rather than stated: an agent can infer it should reach for this when it needs arbitrary vector drawing, and the coordinate paragraph hints at the two placement modes. There is no explicit when-to-use/when-not guidance and no named alternative among the many siblings (insert, text, structure).

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