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

Annotations already declare readOnlyHint=true, so safety is covered, yet the description adds real behavioral context the annotations lack: pagination behavior, the hasMore next-page marker, and the set of returned fields including taskKeys and linked tasks. This is genuinely additive for a read tool.

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?

A single sentence front-loads the purpose and then appends the return/pagination details with no filler. It is dense (the parenthetical field list) but every clause earns its place.

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?

With no output schema, the description compensates by enumerating the returned fields and the pagination flag, and annotations cover the safety profile. Parameters are fully covered by the schema, leaving little an agent must guess to call it 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 100%, so the schema already documents ref, path, page, perPage and repositoryID in detail. The description only echoes 'ref, file or directory' and adds no syntax or format guidance beyond the schema, so the baseline 3 is correct.

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 and resource ('Returns the commit history of a ref, file or directory') and reinforces it with the 'like git log' analogy, which cleanly separates it from line-level siblings such as repo_line_history and repo_blame. It stops short of naming a sibling it is not, so it sits at 4 rather than 5.

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 'like git log' framing implies the usage context, but no explicit when-to-use/when-not or alternative routing is given (e.g., vs repo_line_history, repo_compare, or task_commits). Usage is reasonably inferable but not stated.

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