Add Sticker From Local Path

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

Annotations already declare non-read-only and non-destructive, so the description adds useful context: local mode restriction, supported file formats, and max size. This goes beyond annotations and clarifies operational constraints.

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 concise sentences, each earning its place. Front-loaded with the verb and purpose, immediately followed by usage guidance and technical constraints. 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?

Given the simple tool (3 flat parameters, no output schema, no nested objects), the description provides essential context: local-only operation, file type and size limits. It doesn't describe post-conditions or error behavior, but that's not necessary for this straightforward create operation.

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 already covers all parameters with descriptions, so baseline is 3. The description enhances filePath semantics by adding supported formats (png/jpeg/gif/webp/avif) and max size (8MB), which are not in the schema. This adds real value.

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?

Clearly states the action 'Add a new sticker from an image file on this computer', specifying the resource (sticker) and source (local path). It distinguishes itself from siblings like add_sticker or create_sticker_upload by emphasizing 'local/stdio mode only' and 'by path'.

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?

Explicitly says 'Use when the user gives a local file path' and adds 'local/stdio mode only', providing a clear condition for when to use this tool instead of alternatives. This is excellent guidance.

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