Today summary

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

With no annotations provided, the description carries the behavioral transparency burden. 'Summarizes' does imply a read-only operation, and the output fields are clear, which is helpful. However, the description does not address timezone semantics for 'today', behavior if config_root is missing or misconfigured, or any side effects. It provides adequate but not rich behavioral detail.

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 with the core capability and output fields first. The second sentence adds exactly one relevant edge to call correctly now, and no filler or redundant restatement appears.

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?

Without an output schema, the description still communicates what the tool returns. It also incorporates important context about config_root scoping. It falls slightly short of a 5 because it does not clarify timezone semantics for 'today' or explicitly position itself relative to list_time_entries, which is the most natural sibling alternative.

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 both config_root and workspace_id are already well documented in the schema. The description adds a small amount of value by mentioning the user-scoped config_root scenario, but it does not materially improve parameter understanding beyond the existing schema.

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 uses a specific verb and resource: 'Summarizes today's tracked time,' with concrete outputs (total duration, entry count, per-project totals). This clearly differentiates it from sibling tools like list_time_entries, which covers raw entry retrieval, and get_running_timer, which covers the currently active timer.

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 implies when to use the tool: whenever a summary of today's tracked time is needed. It also gives useful config_root guidance for the current scope. However, it does not explicitly state when to choose this over list_time_entries, create_time_entry, or other siblings, nor does it exclude alternatives, so the usage guidance remains mostly contextual and implicit.

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