excel

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

With no annotations, the description fully discloses behavioral traits: required registry keys (AccessVBOM=1, VBAWarnings=1), Trusted Location setup, need for Excel restart, COM STA serialization causing blocking, and the requirement that macroName must match the Sub name in code. Failure modes (HRESULT 0x800a03ec) are also noted.

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 well-structured with clear sections (Purpose, Details, Prefer, Caveats, Examples). It is comprehensive but each sentence adds necessary information, avoiding redundancy. Front-loading the purpose and distinction aids quick understanding.

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 tool's complexity (VBA execution, COM, permissions), the description covers all essential aspects: purpose, setup requirements, prevalidation, caveats about naming and blocking, and complete examples with return values. No gaps remain despite the lack of an output schema.

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 input schema is empty with additionalProperties: true, so it provides no parameter definitions. The description compensates by defining the key parameters (action, code, macroName, visible) and their meanings, including constraints like macroName must match Sub name. Examples show expected parameter combinations and their effects.

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 the purpose: author and run VBA macros against Excel via COM late binding. It distinguishes from 'Claude for Excel' which writes formulas but cannot run VBA. The two actions run_vba and check_access_vbom are explicitly defined, making the tool's functionality unambiguous.

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 provides direct guidance: 'Prefer: Run check_access_vbom first when a workflow depends on macro execution'. It explains the preflight check and remediation for failures. Examples illustrate correct usage for both actions, clarifying when to use each.

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