index_mark

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

Annotations only declare readOnlyHint=false. The description adds meaningful behavior beyond that: the mark is written as a 'tracked insertion' (a tracked change, explaining the author/tag parameters) and produces an XE field that Word later compiles. This is useful mutation context, though it omits permission/undo behavior.

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 short sentences, front-loaded with the core action and with no wasted filler. Minor awkwardness in the final clause, but overall tight and well-ordered.

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 a mutation tool with no output schema and 7 parameters (86% schema coverage, nested expect object), the description covers purpose, entry format, and the relationship to index_insert. It does not address auth/revision-author requirements or how dry_run/expect behave, but the rich schema fills most remaining gaps.

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 already 86%, so the schema carries most parameter meaning. The description adds one nuance beyond the schema ('up to three levels' for entry depth), but does not clarify tag, author, expect, or dry_run beyond what the schema already states. Baseline 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?

States a specific verb+resource ('Mark an index entry: an XE field') and clarifies the mechanism ('tracked insertion, right after a range'). It also distinguishes itself from the sibling index.insert by explaining that index.insert builds the index from these marks.

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 relationship to index.insert is mentioned ('index.insert puts the index, which Word builds from the marks'), which implies the two-step workflow. However, it never explicitly states when to use index_mark vs the alternative, nor any prerequisites (e.g., that a document must be open). Usage is implied rather than instructed.

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