set_character_spacing

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

No annotations are provided, so the description bears full burden. It explains the effect of spacing_pt (positive expands, negative condenses) but does not disclose permission requirements, error behavior for invalid indices, or whether existing spacing is overwritten.

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 description is extremely concise with one main sentence plus a structured Args list. Every word adds value, and the format is easy to parse. No redundancy or fluff.

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 presence of an output schema (not shown) and the straightforward nature of the tool, the description covers the essential information. It could mention prerequisites (existing paragraph/run) or error handling for out-of-bounds run_idx, but overall it is sufficiently complete.

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?

The description adds meaningful explanations for all three parameters beyond the schema titles: para_id as 'paraId of the target paragraph', run_idx as 'Zero-based index of the run', and spacing_pt with units and direction. Since schema coverage is 0%, this fully compensates.

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 clearly states that the tool sets character spacing (tracking) for a specific run within a paragraph, using precise typographic terminology. It distinguishes from sibling run formatting tools like set_run_size or set_character_position.

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 does not explicitly state when to use this tool versus alternatives, but the parameters (para_id, run_idx) imply the user must first identify the paragraph and run. Among many run formatting siblings, the usage context is clear enough but lacks explicit guidance.

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