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

Annotations already declare readOnlyHint=true, so the read-only nature is covered. The description adds meaningful behavioral context beyond that: it clarifies the tool returns a summary/overview of synced data, not live or unsynced data, and that it can serve as a data-availability check. No contradictions with annotations.

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?

Three sentences with no filler. The core output description is front-loaded, followed by targeted use cases and explicit sibling routing. Every sentence 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?

Given the zero-parameter, read-only, simple-summary nature, the description fully explains what the tool returns, when to use it, and which sibling tools handle adjacent cases. No output schema exists, but the description substitutes for it by naming the exact summary fields. Nothing essential is missing.

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 tool has zero parameters, so the baseline is 4. The description correctly focuses on what the tool returns rather than parameter details, and no parameter clarification is needed.

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?

Description states a specific verb ('Overview') and resource (synced HubSpot data) and enumerates exactly what it covers: portals, contact/company counts per portal, and last sync times. It also explicitly distinguishes itself from sibling tools ask_about_hubspot_contacts and ask_about_hubspot_companies, making the intended scope unmistakable.

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?

Gives explicit use cases: questions about how much HubSpot data exists, which portals are connected, whether data is up to date, and pre-checking data before promising an answer. It also names the alternative tools for record-level questions, providing clear when-to-use versus when-not-to-use guidance.

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