diffctx_context

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is partly covered. The description adds genuinely non-redundant context: the SAFETY note that returned text is untrusted repository content and must be treated as data, which is important prompt-injection guidance. It does not describe output format or token-budget behavior, keeping it below 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 description is compact and front-loaded: purpose first, then usage triggers, then per-parameter hints, then a separated SAFETY block. Every sentence is doing work, though the telegraphic style occasionally costs clarity.

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 9-parameter tool with 0% schema coverage, no output schema and no siblings, the description leaves too much unexplained. The required repo_path and several behavioral parameters (clipboard, include_raw_diff, budget_tokens) are never mentioned, so an agent cannot confidently construct a call.

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 9 parameters, so the description must carry the full explanatory burden. It only annotates three of them (mode with its three values, diff_ref, symbol) and leaves six undocumented — including the required repo_path, plus clipboard, max_tokens, fragment_ids, budget_tokens and include_raw_diff. An agent cannot infer the purpose of the majority of the inputs.

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 states a specific resource — callers, tests and contracts a change reaches outside its diff — which conveys that this is a change-impact/blast-radius analysis tool. The telegraphic noun-phrase style ('Callers, tests and contracts a change reaches...') lacks an explicit verb, but the intent is recoverable. With no sibling tools there is no differentiation burden.

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?

'call before reviewing, committing or pushing' gives explicit, concrete trigger conditions for when to invoke the tool. It stops short of stating when not to use it or what alternatives exist, but the contextual guidance is clear and actionable.

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