change_context

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

With no annotations, the description carries the full burden and does well: it discloses that results are capped, that uncertainty and index versions are reported, that budgets auto-adapt to change risk/fanout, that token_budget overrides this, and that the tool is read-only ('Does not run tests or modify Git'). It omits permission/index prerequisites, which keeps it from a 5.

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 purpose and return contents are front-loaded in the first sentence, and every subsequent clause adds distinct information. It is dense and slightly run-on with mid-sentence semicolons, but there is very little wasted text.

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?

An output schema exists, so return-value detail is not required, and the description still covers comparison modes, budget behavior, and the read-only guarantee. Given 8 undocumented parameters, the definition is not fully complete, but it is adequate for an agent to invoke the tool correctly.

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 0% across 8 parameters, and the description only compensates for a subset: 'comparison' allowed values (working/staged/branch), base_ref's relationship to merge_base, and token_budget's override behavior. depth, max_files, max_symbols, and include_untracked remain undocumented anywhere, leaving real gaps.

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: a Git-diff blast-radius analysis returning changed/removed symbols, transitive consumers, config/schema dependencies, and candidate tests. An agent can tell what it produces. However, it never differentiates itself from close siblings like 'impact' or 'task_context', so routing between them still requires inference.

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?

It explains the 'comparison' modes and how merge_base pairs with base_ref, which implicitly guides which mode to pick, and states 'Does not run tests or modify Git'). But there is no explicit when-to-use, when-not-to-use, or named alternative tool, so the agent must infer the workflow context on its own.

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